Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Treatment of hepatitis B surface antigen (HBsAg) with either chloroform-methanol (2:1, v/v) or 50% 1,1',3,3'-tetramethylurea did not affect the morphological integrity of the particles (about 20 nm in diameter), although the major portion of lipids was released as indicated by their increased buoyant density in CsCl (1.27 g/cm3 as compared with 1.20 g/cm3 for intact HBsAg). The antigenicity and polypeptide composition of HBsAg was not altered by delipidation. The carbohydrate chains of HBsAg contain penultimate beta-D-galactosyl residues. HBsAg was cleaved by chymotrypsin into fragments which were smaller than intact HBsAg by two orders of magnitude and which contained both the a and d determinants.
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PMID:Properties of delipidated hepatitis B surface antigen (HBsAg) and preparation of its proteolytic cleavage fragments carrying HBsAg-specific antigenic determinants. 7 67

Intact Giardia muris cysts were subjected to consecutive chloroform/methanol and 2% sodium dodecyl sulfate (SDS) extractions, and to amyloglucosidase treatment. The SDS-insoluble, amyloglucosidase-fast cyst walls (ACW) were further incubated with chymotrypsin, trypsin, papain, or pronase. Low voltage scanning electron microscopy revealed no discernible change in the ultrastructure of the filamentous layer of the cyst wall following any of these treatments. Affinity for cyst wall-specific monoclonal antibody (Meridian Diagnostics, Cincinnati, OH) was also retained after all treatments. Periodic acid-Schiff staining and gas chromatography/mass spectrometry (GC/MS) of intact and treated cyst hydrolysates showed a significant reduction in the amount of glucose associated with the cyst (72 nmoles/10(6) intact cysts vs 1.9 nmoles/10(6) ACW) as a result of amyloglucosidase treatment, indicating that glucose is stored within Giardia as an SDS-insoluble polymer. Galactosamine was identified by GC/MS as the predominant sugar associated with both the ACW and the proteinase treated ACW (42 nmoles/10(6) ACW). High performance liquid chromatographic analysis of amino acids from intact and treated cyst hydrolysates revealed a marked reduction, but not elimination, of detectable quantities of identifiable amino acid residues (255 nmoles/10(6) intact cysts vs 6.8 nmoles/10(6) proteinase treated ACW). These results suggest that the filamentous layer of the cyst wall is primarily a carbohydrate peptide complex.
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PMID:Carbohydrate and amino acid analyses of Giardia muris cysts. 157 2

An oligopeptide, L-arginyl-glycyl-L-aspartyl-L-serine, having cell attachment activity was synthesized from the respective aminoacids carrying suitable protecting residues, by using carboxymethyl polyethylene glycol (PEG)-modified proteases in organic solvents. Papain, trypsin, and alpha-chymotrypsin were modified with PEG. Organic solvents used were 1,1,1-trichloroethane, chloroform and chloroform/ethyl cellosolve (1:1) mixture. Identification of the products was done by gel permeation chromatography (GPC) and thin layer chromatography (TLC).
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PMID:Enzyme-catalyzed synthesis of a bioactive oligopeptide in nearly anhydrous solvents with polyethylene glycol-modified proteases. 227 20

Human sperm-free seminal plasma (HSP) contains inhibitors (I) of the seminal plasma histone kinase activity (HK). One I is dialyzable and the other I is nondialyzable and precipitable by dialysis of HSP against a hypotonic buffer. When the nondialyzable, precipitable I fraction is resolubilized, it inhibits HK in a concentration-dependent manner. Sephadex G-25 column chromatography of whole HSP resolves I in both the void (Vo) and inclusion (Vi) volumes. Rechromatography of the VoI resolves I solely in the Vo. These and other data suggest that the ViI does not originate from the VoI, and that both I activities represent separate molecular entities. VoI was further characterized and found to be heat labile, trypsin and neuraminidase insensitive, and alpha-chymotrypsin sensitive. VoI is not soluble in CHCl3 or CHCl3:CH3OH (2:1) and is not adsorbed by charcoal. Chromatography of VoI on Sephadex G-100 yields a broad peak of I that migrates just past the Vo. VoI has no detectable cyclic AMP (cAMP) binding activity and VoI activity is not affected by coincubation of VoI and HK with cAMP. VoI also does not bind to zinc-chelate or phenothiazine affinity columns. These data suggest that VoI is protein in nature with properties distinct from the class of previously described protein kinase inhibitors. Although the identity of VoI is not known, it does not appear to be the regulatory subunit of a cAMP-dependent protein kinase, calsemin or a zinc binding protein.
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PMID:Characterization of a seminal plasma-associated inhibitor of human seminal plasma protein kinase. 298 35

Plasmodium berghei sporozoites were observed to react with human hepatoma (HepG2) target cells which had been fixed with methanol, formaldehyde, or glutaraldehyde. The reaction consisted of attachment of sporozoites to the fixed target cells and the release of circumsporozoite protein which bound to target cell areas adjacent to the attachment sites. Treatment of fixed target cells with 0.1 N H2SO4 at 80 C, neuraminidases, neuraminidase plus galactose oxidase or inclusion of transferrin, orosomucoid, their asialo forms, or various monosaccharides in the incubation medium had no significant effect on target cell reactivity with sporozoites. Fixed cells oxidized with periodate or cells extracted with methanol or chloroform-methanol were reactive but lost activity if allowed to air dry after treatment. Treatment with papain or chymotrypsin at levels producing heavy cell structure damage caused a major loss of activity.
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PMID:Plasmodium berghei: reaction of sporozoites with chemically and enzymatically modified hepatoma cells. 301 69

1. The results of this study indicates that the binding of insulin to brain plasma membranes activates a membrane protease which, by a trypsin like mechanism, produces a soluble factor that modulates the PDH behaviour when added to brain mitochondria. 2. The supernatant from brain plasma membranes incubated with 0.5 mg/ml trypsin added to mitochondria increases PDH activity levels and cancels PDH inhibition by NaF, as has already been seen when the plasma membranes are incubated with 25 microU/ml insulin. No such effects are obtained when the incubation is run out with 0.5 mg/ml chymotrypsin. 3. The supernatants from insulin or trypsin treated plasma membranes retain their activating properties on mitochondrial PDH also after dansylation; from these preparations a dansylated active on PDH material was separated by monodimensional chromatography on HPTLC silica Gel plates, using chloroform/1-butanol (93:7 v/v) as a solvent. 4. Insulin incubation of plasma membranes pretreated with protease inhibitors (leupeptin, phenylmethylsulfonylfluoride) or with exogenous trypsin, but not chymotrypsin substrates (esters of arginine and tyrosine) yields an inactive supernatant on PDH. 5. Insulin treated plasma membrane supernatants lose all stimulating properties on PDH after incubation for 1 hr with 2 mg/ml trypsin or chymotrypsin.
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PMID:Evidence of an insulin generated pyruvate dehydrogenase stimulating factor in rat brain plasma membranes. 331 49

The kinetic properties of trypsin have been studied in reverse micelles formed by two surfactant systems, namely bis(2-ethylhexyl) sodium sulfosuccinate (AOT) in isooctane, and hexadecyltrimethyl ammonium bromide (CTAB) in chloroform/isooctane (1:1, by vol.). Three substrates have been used, namely N alpha-benzoyl-L-Arg ethyl ester, N alpha-benzoyl-L-Phe-L-Val-L-Arg p-nitroanilide (BzPheValArg-NH-Np) in AOT and N alpha-benzyloxycarbonyl-L-Lys p-nitrophenyl ester (ZLysO-Np) in CTAB. One of the main aims of the work was to compare the behaviour of trypsin in reverse micelles with that of alpha-chymotrypsin, for which an enhancement of kcat had been observed with respect to aqueous solutions. The pH profile is not significantly altered in reverse micelles with respect to water, however the kinetic parameters (kcat and Km) differ widely from one another, and are markedly affected by the micellar conditions, in particular by the water content wo (wo = [H2O]/[AOT]). Whereas in the case of BzPheValArg-NH-Np kcat is much smaller than in water, in the case of ZLysO-Np at pH 3.2 (but not at pH 6.0) a slight enhancement with respect to water is observed. On the basis of rapid kinetic spectrophotometry (stopped-flow) and solvent isotope effect studies, this enhancement is ascribed to a change in the rate-limiting step (acylation rather than hydrolysis). As in the case of alpha-chymotrypsin, the maximal activity is found for all substrates at rather small wo values (below 12), which is taken to suggest that the enzyme works better when is surrounded by only a few layers of tightly bound water. Spectroscopic studies [ultraviolet absorption, circular dichroism (CD) and fluorescence] have been carried out as a function of wo. Whereas the absorption properties are practically unchanged, the CD spectrum in AOT micelles has a lower intensity than in water, which is interpreted as a partial unfolding. The intensity is partly restored when Ca2+ ions are added, indicating that the micellar environment may cause a partial denaturation by depleting it of calcium ions. Fluorescence data show that the emission properties of the protein in reverse micelles match those in aqueous solution at around wo = 13 approx., whereas lambda max shifts towards the red by increasing wo, indicating an exposure of the tryptophan residues and probably an unfolding of the whole protein, at wo values above 15. Finally the reaction between trypsin and its specific macromolecular Kunitz inhibitor from soybeans is studied.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Structure and activity of trypsin in reverse micelles. 336 18

Corynebacterium glutamicum CBII, in the stationary phase of growth, was found to produce spontaneously a substance resembling bacteriocins by its bactericidal properties. This substance designated glutamicin CBII was observed to exhibit bactericidal activity against coryneform bacteria (12 species tested) but not against unrelated gram-positive (3) and gram-negative (3) bacteria, while its action on bacteria with no quite known relatedness to the coryneform group (14) was found to be variable. Glutamicin CBII was partially purified by precipitation with ammonium sulphate (70% saturation), selective heat precipitation and gel chromatography on Sephadex G-50. The antibacterial substance diffused through cellophane membrane with an approximate cut-off of 10,000 dalton and its sedimentation coefficient was determined to be 1.1 S by ultracentrifugation. Heating at 100 degrees C for 30 min had no effect on its activity. Glutamicin CBII was proved to be resistant to chloroform, trypsin, chymotrypsin, pronase, and subtilisin. According to its staining behaviour and 1H NMR spectra it probably represents a glycoprotein containing only a minor protein component.
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PMID:Glutamicin CBII, a bacteriocin-like substance produced by Corynebacterium glutamicum. 372 73

The binding of [14C]dicyclohexylcarbodiimide (DCCD) to soluble complex III from yeast mitochondria was examined under conditions which resulted in the inhibition of proton ejection but had a minimal effect on cytochrome c reductase activity. Incubation of the complex with 50-100 nmol of [14C]DCCD/nmol of cytochrome b at 12 degrees C did not result in any changes in the appearance of the high-molecular-weight subunits (I-V) after sodium dodecyl sulfate-gel electrophoresis, although a slight broadening of the three lowest molecular-weight subunits (VI-VIII) was observed. The [14C]DCCD was bound preferentially to subunit III (cytochrome b) and a wide band with an apparent low-molecular weight ranging from 8000 to 9000 to less than 2000 depending on the gel system used. Extraction of the [14C]DCCD-treated complex III with chloroform:methanol had no effect on subunit III but completely removed the low-molecular-weight radioactive band. Thin-layer chromatography of the chloroform:methanol extract revealed that the radioactive material extracted from the [14C]DCCD-treated complex III migrated with the same apparent RF as either free [14C]DCCD or cardiolipin. Amino acids were not detectable in an acid hydrolysate of the chloroform:methanol extract, suggesting the absence of protein. Digestion of the [14C]DCCD-treated complex III with either chymotrypsin or Staphylococcus aureus V8 protease resulted in the decrease of both staining intensity and labeling in subunit III but had no effect on the radioactivity in the low-molecular-weight material. These results confirm that DCCD binds preferentially to cytochrome b in complex III from yeast mitochondria and suggest that cytochrome b may play an important role in proton translocation at this site of the respiratory chain.
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PMID:The preferential binding of dicyclohexylcarbodiimide to cytochrome b and phospholipids in soluble complex III from yeast mitochondria. 608 3

The morphology of peptidoglycan layer of Rhizobium cell wall was examined by transmission electron microscopy. Peptidoglycans were isolated from intact cells after treatment with sodium dodecyl sulfate, extraction with aqueous 45% phenol and then with a mixture of chloroform-methanol. Finally rigid layers were digested with trypsin and chymotrypsin. The results indicate the presence of lump or bar-like structures on the surface of the cell shaped peptidoglycan sacculi. Evidence is provided suggesting that the cellulose microfibrils arise directly from these excrescences found on the peptidoglycan surface. Digestion with cellulase removed all cellulose microfibrils whereas the lumps and bars remained as an integral part of the Rhizobium peptidoglycan.
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PMID:Structure of the rigid-layer of Rhizobium cell wall. III. Electron microscopic evidence for the cellulose microfibrils association with peptidoglycan sacculi. 619 47


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